Ok, I'm crunching numbers and working out plans to go to ESP in the future. One question I have pertains to exhaust. If you read the LT1 tech board everyone raves about longtubes. However since we actually spend more time at the lower end of the RPM band, which is better for auto-x? I am considering MAC 1 5/8" midlength headers, AS&M 1 3/4" midlenth headers, or Jet-Hot 1 3/4" full longtube headers. Yes, the 1 3/4" sizes will be better in the top end but with auto-x I want to maximize torque. I'm leaning towards MAC. Any comments and actual experiences with these? Also, from what I know the 1 5/8" primaries will help maintain lower RPM torque vs. the 1 3/4". The other element to consider is ground clearance. The car will be a semi-daily driver but would be lowered ~1" with coilovers. Many claim clearance problems w/ LT's when lowered. I already have a car that is slammed and scraping is a pain in the a$$.

 

wow! no one has any comments on this?

 

IMO you will not be happy with longtubes if your car is lowered at all. Hell I wasn't happy with mine at stock ride height. These cars just were not designed to have a pipe run down the driver side and thats what you get with longtubes.

Personally I would get the AS&M's (or MAYBE SLP's). The Mac's are a good design as well but I would want 1 3/4" primaries.

 

I've been pondering the same thing since my LT1 is now is
ESP.

 

Long tubes are nice. And if I were buying longtubes I would buy the FLP longtubes. I can't tell someone yeah go buy those because they may scrape. But I do know that Bob Anderson (the Yellow Camaro at Nationals) has FLP's on his LT1 and he said last year he gets very very little to no scraping. I know he drives the car more this year on the street but I have not asked.

Long tubes will fatten the torque curve BUT I have a feeling what you gain by having the longtubes you lose by having the 1-3/4" tubing.

I currently have a set of Hooker short tube headers. The gain just was never there. At least the one I expected. So I will make some changes.

Next season I will have 'Hooker short tubes' but I will have welded a long collecter on to them. This will make them more of a mid-length headers. The collector will actually extend the header pipes themselves 4-5 inches as well.

After the headers will be the modified Y-pipe, a new stock cat converter and a Shonefeild 3"inlet outlet 8" long race muffler. It is similar to a glaspack only not glasspacking. Then add a turn down. At some point I will also dyno test before and after adding a Vertex cone muffler inside the turn down. Just to see I pick up any torque.

The reason for going to this exhaust is that it will be about 60lbs lighter than the Borla exhuast that is on now!

 

Personally I had a bad experience with my MACs that I had bought for my '96. I later went to FLP. I know that the MACs are different for the '95-'97 cars, so it maybe just them that were not very good.

I now have MACs 1 3/4" shorties on my LS1 and I saw dramatic increases. The only real problem that I had, was install. I had to drop the motor about 2" out of the car to fit them in.

I autocross the hell out of my '99, I can't say that the torque curve moving up away from the lowend has hurt me much, most of the courses I've been on I can run in either 2nd or 1st. very rarely staying low in the rpm range.